package com.example.ex_5;

import androidx.appcompat.app.AppCompatActivity;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CursorAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.SimpleCursorAdapter;

public class Main3Activity extends AppCompatActivity {
    SQLiteDatabase db;
    Button bn = null;
    ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        db=SQLiteDatabase.openOrCreateDatabase(this.getFilesDir().toString()+"/my.db3",null);
        listView = (ListView)findViewById(R.id.show);
        bn = (Button)findViewById(R.id.ok);
        bn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String title = ((EditText) findViewById(R.id.my_title)).getText().toString();
                String content = ((EditText) findViewById(R.id.my_content)).getText().toString();
                try {
                    insertDate(db, title, content);
                    Cursor cursor = db.rawQuery("select* from news_inf", null);
                    inflateList(cursor);
                }
                catch (SQLiteException se) {
                    db.execSQL("Create table news_inf(_id integer primary key autoincrement," + "news_title varchar(50)," + " news_content varchar(255))");
                    insertDate(db, title, content);
                    Cursor cursor =db.rawQuery("select* from news_inf", null);
                    inflateList(cursor);
                }
            }
        });
    }
    private void insertDate(SQLiteDatabase db,String title,String content){
        //执行插入
         db.execSQL("insert into news_inf values(null , ? , ?)", new String[]{title , content});

    }
    private void inflateList(Cursor cursor){
        SimpleCursorAdapter adapter=new SimpleCursorAdapter(Main3Activity.this,R.layout.activity_line,cursor,new String[]{"news_title","news_content"},new int[] {R.id.my_title,R.id.my_content}, CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
        //显示数据
        listView.setAdapter(adapter);
    }
    @Override
    public void onDestroy(){
        super.onDestroy();
        if(db!=null&&db.isOpen()){
            db.close();
        }
    }
}
